Influence of voltage and distance on quality attributes of mixed fruit beverage during pulsed light treatment and kinetic modeling

摘要

The study investigates the influence of pulsed light (PL) processing parameters on quality of mixed fruit beverage followed by kinetic modeling. The attributes tested were aerobic mesophiles (AM), yeast and mold (YM) counts, polyphenol oxidase (PPO) and peroxidase (POD) activity, color change (Delta E*), browning index (Delta BI), antioxidant capacity (AOC), and ascorbic acid (AA) content at varying voltage (1.8-2.4 kV), the number of pulses (2-187), and distance (2.4-9.6 cm). Weibull model described the PL inactivation rate of AM and YM andnthorder kinetic model estimated the inactivate rate of PPO, POD, and AA. The maximum inactivation of PPO, POD, and AA content were 41, 51, and 36%, respectively. At the most severe PL condition, Delta E* was 6.4, Delta BIwas 5.6 with 14% increment in phenolics. A secondary kinetic model adequately predicted the ratio of rate constant and fluence-based rate (k/k(F)) for PPO, YM, and AA correlating voltage (V) and lamp distance (x). PL-induced pasteurization of the beverage is possible at the fluence rate of 17.42 W/cm(2)for 3 min. Practical Applications Exposing the food material to a high intensity pulsed light (PL) is a nonthermal way of food preservation for the shelf-life extension. The potential of PL treatment (PLT) has been explored for a mixed fruit beverage in terms of its microbial, enzymatic, and nutritional quality. An optimized PLT condition is proposed to obtain a microbially safe fruit beverage along with a minimal loss in bioactive compounds. Subsequently, the kinetic data related to microbial and enzyme inactivation and degradation of vitamins will help in deciding the process parameters like treatment time, lamp voltage, and sample distance from the light source. The secondary kinetic model will eventually help to design a robust PL process condition for similar fruit beverages to obtain a microbiologically safe product with a minimal loss in vitamins.